1. Field of the Invention
The present invention relates to a following distance alarming apparatus for measuring a distance from a vehicle equipped with the following distance alarming apparatus (hereinafter, simply referred to as xe2x80x9csubject vehiclexe2x80x9d) to a vehicle running ahead (hereinafter, simply referred to as xe2x80x9cpreceding vehiclexe2x80x9d) to prevent collision of the subject vehicle against the preceding vehicle based thereon, and a following distance displaying apparatus for displaying the following distance and/or its change.
2. Description of Related Art
Vehicles such as automobiles move independently from each other on a road. Therefore, there might occur an accident such as bumping of vehicles. On a superhighway, in particular, the frequency of rear-end collisions is higher and a high vehicle speed is liable to invite serious results.
The major cause of collision is a following distance that is too short. Under these circumstances, apparatuses have been conventionally proposed for preventing a collision accident between a subject vehicle and a preceding vehicle by using a following distance measuring device. The applicant of the present invention also proposed a following distance informing apparatus for informing a change of a following distance in the U.S. Pat. No. 6,119,068.
These related art advantageously allows drivers to cope with a change of the following distance with ease since change of a following distance can be informed of the drivers. The related art, however, has such a problem that when a following distance changes every moment, it is difficult for drivers to instinctively apprehend the change.
An object of the present invention is directed to improvement of a following distance alarming apparatus such as the above-described rear-end collision alarming apparatus, collision predicting apparatus and following distance informing apparatus and is to provide a following distance alarming apparatus which accurately copes with a following distance changing every moment.
Another object of the present invention is to provide a following distance alarming apparatus enabling operation conditions of each of the above-described apparatuses to be apprehended at a glance to increase practicability and reliability as an index for safety driving.
A following distance measuring apparatus according to one aspect of the present invention for achieving the above objects includes a following distance measuring device, a memory responsive to the detection of a preceding vehicle and a subject vehicle having a follow-up travel state for a predetermined time based on a following distance to the preceding vehicle measured by the following distance measuring device for storing an output signal value from an operation member operative according to a speed control apparatus of the subject vehicle, an alarming apparatus responsive to a distance predetermined corresponding to a following distance at which the follow-up travel state is attained being measured by the following distance measuring device for determining a possibility of collision based on an output signal value from the operation member and an output signal value stored in the memory to output a warning, and a control circuit for, after the follow-up travel state is maintained for a predetermined time, upon another detection of the preceding vehicle and the subject vehicle having the follow-up travel state for a predetermined time, causing the memory to newly store the then output signal value from the operation member and further in response to the measurement of a distance predetermined corresponding to the then following distance and further based on the output signal value from the operation member and the newly stored output signal value, controlling the alarming means to determine a possibility of collision and output a warning.
A following distance displaying apparatus according to another aspect of the present invention includes a following distance measuring device, an alarm generating apparatus, a displaying apparatus capable of displaying a distance at which the alarm generating apparatus operates, and a control circuit for detecting a following distance to a preceding vehicle measured by the following distance measuring device attaining a predetermined following distance to control the alarm generating apparatus to inform the danger of collision, as well as controlling the displaying apparatus to display the distance at which the alarm generating apparatus operates after the preceding vehicle and the subject vehicle maintain a follow-up travel state for a predetermined time.
In addition, a following distance displaying apparatus according to a further aspect of the present invention is one that is intended for a vehicle and used connected with a following distance measuring device and includes a displaying apparatus for displaying a following distance measured by the following distance measuring device, a memory, and a control circuit responsive to an output signal from an operation member operative according to a speed control apparatus of a subject vehicle and responsive to satisfaction of a condition having a predetermined relation with a following distance measured by the following distance measuring device for controlling the displaying apparatus to display, based on the then output signal value from the operation member, a pointer indicative of a change of a signal value from the operation member on the displaying apparatus.
A following distance displaying apparatus according to a still further aspect of the present invention includes a displaying apparatus for displaying a following distance to a preceding vehicle measured by a following distance measuring device, an alarm generating apparatus for generating a warning based on detection of a predetermined following distance, an input device operable by an operator of a vehicle, and a control circuit responsive to operation of the input device for controlling the displaying apparatus to display a distance at which the alarm generating apparatus operates which is determined by a predetermined method, the control circuit controlling the displaying apparatus to display a difference between a distance to the preceding vehicle measured by the following distance measuring device and a distance at which the alarm generating apparatus operates by the operation of the input device.
The foregoing and other objects, features, aspects and effects of the present invention will become more apparent from the following detailed description of the present invention with reference to the accompanying drawings.